I've recently wired my 41 ford with a Rebel 9+3 wire harness. And I'm having problems with my battery dieing. I had this problem before the rewire and was hoping rewiring the car would fix my problem due to the poor wiring done the first time. But the problem still persist. I've already replaced both the battery and alternator in the car and still have the same problem. The alternator seems to be working correctly (produces around 14.7v under load). but once i shut the car off the battery starts to loose voltage. I'm running a chevy 350 in it and was wondering if maybe I'm missing something between the alternator and battery, like a voltage regulator, relay, or solenoid maybe? Once the car is off i can hear the alternator making a high pitch buzzing sound, like voltage it feeding back thru it. It's the same sound i heard on the original alternator which made me think it was bad. Now I'm not so sure. Other than headlights, tail lights, blinkers, and ignition system i don't have anything else connected to the electrical system, it's pretty bare bones at the moment.
Very simple test. Remove the negative battery cable and put a test light between it and the post. If you get any light at all you have something drawing current. Start unplugging things until the light goes out. I suspect something either in the alternator or the alternator wiring setup. They have a diode in them that keeps current flowing one way and they do fail. I had 3 bad alternators in a row one time at the parts store, the rebuilders fix the first thing they find bad and forget about other problems one may have when they rebuild them. Don
disconnect the alternator and see if the problem goes away. its possible that you have the wires on the pigtail reversed which would leave it turned on all the time.
The pigtail currently has one jumpered to the the 12+ post and the other is connected to the alt. exciter wire. I wasn't sure if that's how it suppose to connect so i had called Rebel Wire and that's how they told me to connect it. should i swap there positions and see if that alleviates the problem? Originally neither of the pigtail wires where connected to anything. just the 12+ to the battery.
I work on cars everyday and can't remember an alternator making noise with key off! GM alt? With alt making noise key off first I'd disc two pin comnector. Does noise go away? Then disc heavy output wire? Better? I definitely would equate alt noise key off to dying battery!
Yeah its a chevy alt. can't say i've ever heard one buzz either until i got this car now i've had 2 that do it. I thought maybe i was missing a part of the charging system between the battery and alt that might be causing the back feed. My car is Frankensteined so much its ridiculous. Even the motor has parts from different year models on it. It's a 350 out of a 80-85 model truck but the accessories and their mounts are out of a 90's model chevy of some sort. found that out when i went to get the alt. replaced the first time. I'll check it with a test light to make sure that its the alt. but thats what i think the culprit is even though its new. Just hope that if i have to replace it again it fixes the problem this time.
Chevy alt wiring is pretty simple. I'm trying to think what wiring malady would cause dying battery and alt noise engine off??? At our shop we always have our full- service auto parts store put any alt in question on the alt machine to see if it charges and if it's too noisy under load. Take alt to auto parts and see if it makes noise after they hook it up BEFORE they spin it? Not counting ground ckt through case there are three wires? Heavy output wire and two at connector? The BROWN wire is usually wired through GEN, ALT, or BATTERY idiot light. Believe it or not, that's very important. Third wire is charge V sense wire for integral reg. Like I said, simple. I see the two pin connector reversed often enough. But that doesn't make alt noise. With ignition key on should see power at all three wires. If you use a test light the brown wire from idiot light will be dim, but light up.
yeah there is the 12+ large post and then a connector with 2 wires both of which are brown/white. per the wire harness instructions i connected one to the 12+ post and the other to the alt exciter wire. I don't have a light or volt meter on my car at the moment. I might have the 2 wires connected backwards that's pretty probable due to both being the exact same colors. Though before i rewired the car i had the same problem and the 2 brown/white wires were not connected at all. Just the 12+ post. And the buzzing sound it makes isn't loud. In fact some people can't even hear it.
Try this...If the GM alt is the 10si model, take the 2 wire pigtail and 'Y' it (merge) to one wire that will be keyed ignition on/off
Yep that's how i have it wired currently. minus the indicator light. Granted i could have the 2 plug wires backwards
First off, get a multimeter or volt meter of some sort. It's an absolutely indispensable tool imo. Then take your meter and measure voltage (with the key off) at your exciter aka idiot light wire. If it shows 12v with key off, there's your problem. To me the sound indicates that the alternator is always getting power and therefore draining your battery (which is rather ironic haha). Try unpluggung the two pin connector, does the sound go away?
Use that diagram and verify wires are going to the correct terminal. Is the exciter wire going to your acc. terminal of your ignition switch? It should be if you are not going to use diode or idiot light. The buzz sounds like the alternator is trying to motor. A real easy way to check is to remove fan belt and see what the alternator is doing. No movement is what you should see.
It has been a while since i was last able to work on this problem. But I am still having problems with my battery going dead on me. I know that it is the alternator causing the draw on the battery. Is it because i need some sort of resistance between the wire and the Alt.? There is no idiot light or volt meter in the car. Here are a couple of photos of how it is wired. Never thought 3 wires would give me such a headache. The L brown/white is connected to the Alt exciter wire and the F brown/white is connected to the 12+ post as the instructions indicated. With this configuration I am getting a .6 amp draw. If i reverse the wires i get 1.6 amp draw.
no you have to be at the front of the car with the hood open to hear it. And some people don't hear it at all. I just tried merging the pigtail and connecting it to the Alt exciter wire. Like Rustyangels suggested. That does stop the current draw but also seems to make the Alt. not charge so that won't work.
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